The use of communication systems having wireless mobile communication units has become widespread. Wireless communication systems that operate within a cell or coverage area provide several important advantages over conventional wired systems. For example, wireless communication users can communicate in locations where wired service is not available or feasible, such as remote or rugged locations. Additionally, wireless communication users within the cell have much more mobility, because the units do not have to be connected to a fixed wired network. These and other favorable characteristics make wireless communications ideally suited for personal, business, military, search and rescue, law enforcement, water vehicle, and other field related applications.
Common approaches to providing wireless communication systems include two-way radio systems and cellular systems. Despite the benefits of these approaches, they have several drawbacks. First, the cell size or range of units within these systems depends, at least in part, upon the power provided to the units. Typically, disposable or re-chargeable batteries are incorporated into wireless communication devices to provide operating power to the devices. The batteries can provide different amounts of power to units, depending on the size and/or weight of the batteries. For instance, a small battery may provide on the order of 100 milliwatts to a unit, and may be compact and lightweight enough to be incorporated into a cellular telephone. However, such a small battery provides only enough power to facilitate a range of a few miles, and only for a few hours.
It is for this reason that a plurality of fixed base stations or towers need to be constructed within a couple of miles of one another to make cellular systems effective. The towers define multiple cells and serve to, among other things, receive the weak signals transmitted by cellular telephones, so as to achieve usable range even as the cell phones themselves achieve only a short range. The towers also extend the operating life of the cell phone batteries, by enabling the units to transmit at a low power level. However, such towers are expensive, and take a substantial amount of time to construct. The cost of building such base stations is not warranted in some instances, such as in extremely remote areas. And, it may not be possible or desirable to build towers at other locations, such as on battlefields or in war zones, where the communication coverage area or cell needs to remain mobile, and the towers themselves would represent vulnerable targets for the enemy. Accordingly, aircraft mounted communications systems have been implemented within aircraft to provide mobile base stations for servicing an associated coverage area.
Traditionally, airborne electronic equipment, for example, as might be utilized in an aircraft mounted communications system, is implemented aboard aircraft in a packaging style referred to as Line Replaceable Units (LRUs). The phrase “Line Replaceable Unit” refers to a black box of electronics, such as a radio or other auxiliary equipment for a complex engineered system like an airplane or ship. LRUs speed up installation and repair, because they can be installed or replaced quickly. Typically, they also reduce the cost of systems, and increase the quality, by spreading development costs of the type of unit over different models of vehicles.
In aircraft implementations, many LRUs come together to comprise a payload or the load (in this case the electronics) which the vehicle is designed to transport under specified conditions of operation, in addition to the aircrafts own unladed weight. In these instances the payload determines the operational capabilities of the aircraft. Typically these loads are oriented to missions such as surveillance or communications. As a part of the aircrafts payload, LRUs are typically mounted in aircraft equipment racks. Although these equipment racks vary in size and construction (depending on the aircraft) they uniformly provide the means to house the LRU and to secure the LRU to the aircraft. Due to the weight and size, the mounting rack is generally bolted into the aircraft before loading and integrating its intended LRUs and cables. Final integration of LRUs, are required to occur on site with the aircraft, and results in a time consuming effort. This necessary process is a burden on time and cost.